Transcript ANTIMICROBIAL AGENT (PENGAWET)

Kuliah Bahan Tambahan Makanan
Universitas Padjadjaran
2011
PENDAHULUAN
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PERLU
PENCEGAHAN
PENDAHULUAN
 Bahan pengawet
senyawa yg mampu menghambat dan
menghentikan proses fermentasi,
pengasaman atau bentuk kerusakan lainnya
dan dapat memberikan perlindungan bahan
pangan dari pembusukan.
WHY???
consumer expect food to be:
- available year round,
- free of food-borne pathogen,
- to have reasonably long shelf-life
TUJUAN PENGGUNAAN PENGAWET
SIFAT ANTIMIKROBIA
 Menghambat pertumbuhan mikrobia dg cara:
1. Gangguan sistem genetik
2. Menghambat / mengganggu dinding sel ataupun membran sel
3. Pennghambatan enzim
4. Pengikatan nutrient esensial
Factor in selecting antimicrobial
agent:
 The antimicrobial spectrum of the compound to be
used must be known.
 Chemical & physical properties of both the
antimicrobial and the food product must be known
 The condition of storage of the product and
interaction with other processes must be evaluated to
ensure that the antimicrobial will remain functional
over time.
 A food must be of the highest microbiologically
quality initially if an antimicrobial is to be expected to
contribute to its shelf-life.
PERSYARATAN BHN PENGAWET YG
BAIK
1. Memiliki arti ekonomis dr pengawetan
2. Hanya digunakan jika cara pengawetan tdk
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mencukupi
Memperpanjang umur simpan
Tidak menurunkan kualitas
Mudah dilarutkan
Aman dlm jmlh yg diperlukan
Mudah dianalisis
Tidak menghambat enzim pencernaan
Tidak bersifat toksik
Spektra antimikrobia yg luas.
JENIS BAHAN PENGAWET
 PENGAWET ORGANIK
terdiri dari asam-asam organik dan garamnya, seperti
asetat, benzoat, propionat, sorbat, epoksida, dll.
 PENGAWET ANORGANIK
- digunakan dlm bentuk garam seperti nitrit,
metabisulfit
- dalam bentuk gas seperti sulfit (SO2)
- dalam bentuk liquid seperti hidrogen peroksida
ORGANIC ACID
 Commonly used as antimicrobial preservative or
acidulan
 The activity related to pH and generally limited to pH
< 5,5
 Mechanism:
- organic acid influence cell walls synthesis in
prokaryotes.
- organic acid likely act at the cytoplasmic membrane
level. Organic acid penetrates the cell membrane
bilayer, and once inside the cell it dissociates because
the cell interior has a higher pH than exterior.
a. Acetic acid & acetate salt
 More effective against yeast & bacteria
 The activity depend on product, environment, and
microorganism.
 Application:
- addition of acetic acid at 0,1% to scald tank water used in
poultry processing ddecrease the salmonella &
campylobacter (okrend et al., 1986)
- used as a spray sanitizer on meet carcases effective for
beef, lamb, & catfish fillets. Use of 2 % acetic acid resulted
reduction in viable E. coli.
- added at 0,1% to bread dough inhibited growth bacillus
subtilis in wheat bread (pH 5,14) > 6 days.
 Sodium acetate is an inhibitor of rope-forming bacillus
in baked goods and of the mold.
 It is useful in the baking industry because t has little
effect on the yeast used in baking.
b. Benzoates & other
 Primary uses as antimycotic agent (most yeast and mold)
 Benzoates are most effective at pH 2,5 – 4,0.
 Mechanism: benzoic acid destroyed the proton motive
force of the cytoplasmic membrane by continous transport
of proton into the cell causing disruption of the transport
system.
 Benzoates also inhbit enzymes in bacterial cell as those
controlling acetic acid metabolism & axydative
phosphorylation.
 Benzoates had no carcinogenic effect were given 1 – 2% and
nonmutagenic.
Other organic antimikrobial agents
 Lactic acid is primary used to many fermented diary,
vegetable, and meet product. It is usually used as a
food additive for pH control & flavoring.
 Propionic acid & propionate use to against mold, yeast,
& bacteria gram negative. Usually used in baked goods
& cheese.
 Sorbic acid & sorbates have been used in food as
effective inhibitor of fungi, including that produce
mycotoxin, and certain bacteria.
PARABENS
 Parabens: alkyl ester of p-hydroxybenzoic acid.
 Effective at pH 3-8 (effective at acidic an alkaline pH),
and generally more active against mold & yeast than
bacteria.
 Mechanism: is most likely related to their effect on
cytoplasmic membrane. The parabens were capable of
inhibiting both membran transport and electron
transport system.
 To take advantage solubility & increased activity,
methyl and propyl parabens are normally used in a
combination 2-3 : 1
 The used of parabens are application in beverages, soft
drink, jelly, juice, salad, etc.
 The FDA consider parabens total addition limit of 0,1%
NITRITES
 Nitrite salt (KNO2 & NaNO2 ) primarily used to
inhibit the growth and toxin roduction of C.
botulinum in cured meats.
 Nitrite is most inhibitory to bacteria at acidic pH
and more inhibitory under anaerobic condition
 Mechanism: the inhbitory effect f nitrite on
bacterial sporeformers is apparently due to
inhibition of outgrowth and during cell division.
 Nitrite does not inhibit spore germination to a
significant extend. Nitrite inactivated enzymes
associated with respiration .
 Lethal dose of nitrites in human is 2 – 6 g,
prolonged ingestion nitrite cause
methemioglobinemia, that is, excessive production
of abnormal mioglobin.
NATAMYCIN
 Natamycin or pimaricin ( C33 H47 NO13 )is a polyene
macrolide antibiotic.
 Natamycin is active against nearly all molds and yeast,
but no effect on bacteria or viruses.
 Several factors affect the stability & resulting
antimycotic activity of natamycin:
-pH, 100% natamycin activity is retained at pH 5 - 7
-temperature, high temperature will decrease activity
-light,
-oxidant,
-heavy metal.
 Mechanism: polyene macrolide antibiotic is binding to
ergosterol & other sterol group of the fungal cell
membrane.
 Generally, binding of the natamycin by sterol causes
inhibition of ergosterol biosynthesis and distortion of
the cell membrane with resultant leakage.
 Application: cheese, baking industry, fruits, and meets
as a mold spoillage inhibitor.
DIMETHYL DICARBONATE (DMDC)
 The primary target microorganism for DMDC are
yeast.
 It was more effective than sorbate & benzoate. Mold
are generally more resistant to DMDC than yeast or
bacteria.
 DMDC used in product: wine, teas, carbonated &
noncarbonated juice beverages, and carbonated &
noncarbonated nonjuice beverages.
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Other antimicrobial agents
 Lysozyme (1,4-β-N-acetylmuramidase), catalyzes
hidrolysis peptidoglican of bacterial cell walls.
 Nisin, peptide produced by a strain of dairy starter
cultur L. lactis
 Phosphates
 Sulfites
Pelanggaran Penggunaan
Pengawet
 Menggunakan bahan pengawet yang dilarang
penggunaannya untuk pangan.
 Menggunakan pengawet melebihi dosis yang
diizinkan.
PENGAWET DILARANG
 Formalin (pengawet mayat)
 Asam Borat (Boric Acid) dan senyawanya
 Antibiotik (Chloramphenicol)
 Asam Salisilat dan garamnya (Salicylic Acid and its
salt)
 Dietilpirokarbonat (Diethylpirocarbonate DEPC)
 Kalium Klorat (Potassium Chlorate)
 Kalium Bromat (Potassium Bromate)
 Nitrofurazon (Nitrofurazone)
CASE STUDY
 Pemutaran video repostase investigasi dg judul/kasus:
“penjualan otak-otak berbahaya pengawet”
QUIZ PEWARNA
1. Jelaskan pengertian pewarna tambahan makanan
dan sebutkan 3 jenis pewarna sintetik!
2. Sebutkan & jelaskan sifat fisikokimiawi dr
pigmen klorofil!